Mold can stick to some of the furniture even if it's not a large, visible spot. When mold developed on the wall behind your large wardrobe there's a good chance that the wooden back of the dressed caught a bit of it. You move to a new place and carry the spores with you. At worst the new place also has a humidity problem and the spores you brought accelerate the mold development process.

Anything that sat around a mold infested area is something you should look at closely, at least to proactively give it a thorough scrub and dry in a well ventilated area before bringing in the house.

An air filer with a real HEPA filter will help catch airborne spores but if you already have mold growth anywhere in the room you need to take care of that before blowing air all around.